Narrow gap applications of swing TIG-MIG hybrid weldings

To solve the lack of sidewalls penetration in gas metal arc welding (GMAW), a swing TIG-MIG hybrid welding method was proposed and applied in the narrow gap welding. The arc shapes and voltage changes in MIG, TIG-MIG hybrid welding and swing TIG-MIG hybrid welding were compared. The result reveals that the swing TIG-MIG hybrid welding can be used in narrow gap welding to attain good sidewall penetration. The assisted TIG arc can widen the MIG weld width and obtain good sidewall penetration, and stabilize the MIG welding voltage thereby improving welding quality. The melted welding wire in the MIG welding molten pool will spread to the TIG welding molten pool, which makes the weld width increased and the welding spread improved.